Referring to FIG. 1, one example of a background nonvolatile (NV) memory card is explained. As illustrated in FIG. 1, a background nonvolatile (NV) memory card 102 includes a nonvolatile (NV) memory 104 and a memory card controller 108 for reading and writing the NV memory 14 and for interfacing with a host computer 120. As also illustrated in FIG. 1, the background NV memory card 102 is inserted into a card inserter 124 of the host computer 120. The host computer 120 includes a memory card host controller 122 which can read and write data relative to the background NV memory card 102 placed in the card inserter 124.
The background NV memory card 102 of FIG. 1 is provided with only one nonvolatile (NV) memory card controller 108 and, therefore, it may have no compatibility to other nonvolatile (NV) memory card host controllers in conformance with different standards of nonvolatile memory card. On the other hand, since the host computer 120 is provided with one card inserter 124, more than one NV memory card cannot be installed at a time. Under such a circumstance, another nonvolatile (NV) memory card 202 shown in FIG. 2 has been introduced. As illustrated in FIG. 2, the NV memory card 202 includes first and second nonvolatile (NV) memory card controllers 208a and 208b which allow the NV memory card 202 to have compatibilities to two different standards of nonvolatile memory card. That is, the NV memory card 202 can be installed in two different host computers having different nonvolatile memory card host controllers.
In the NV memory card 202, each of the first and second NV memory card controllers 8a and 8b receives an interface signal S1 and a select signal S2 from a host computer (not shown) to exchange data with the host computer. The interface signal S1 transmits data to and from the first and second NV memory card controllers 8a and 8b, and the select signal S2 switches between the first and second NV memory card controllers 8a and 8b. 
The NV memory card 202, however, raises a problem of large circuit size since the first and second NV memory card controllers 208a and 208b include nonvolatile memory controllers 206a and 206b, respectively, each for controlling the NV memory 104.
In addition, if the NV memory 104 has some restrictive conditions for access from the NV memory controllers 206a and 206b, for example, these conditions may affect the first and second NV memory card controllers 208a and 208b. In other words, in such a case, it may not be possible to apply any kinds of nonvolatile memory card controller to be installed in the NV memory card 202.
FIG. 3 shows another nonvolatile (NV) memory card 302 in which each of first and second NV memory card controllers 308a and 308b is configured to directly access to the NV memory 104. Accordingly, a nonvolatile memory card controller using a physical data format permitted by the NV memory 104 can only be applied. Otherwise, any nonvolatile memory card controllers cannot be usable.